QNT 2020 QUESTIONS WITH VERIFIED ANSWERS
In a bimodal histogram, the two highest bars will have the same height. - Answers -
False: Not necessarily, though they might be the same.
A frequency distribution is a tabulation of n data values into classes called bins. -
Answers - True: This is the definition of a frequency distribution.
The coefficient of variation is - Answers - A unit-free statistic.
Outliers are data values that fall beyond ±2 standard deviations from the mean. -
Answers - False: Outliers are 3 standard deviations from the mean
In a left-skewed distribution, we expect that the median will be greater than the mean. -
Answers - True: When there is left skewness, the mean is likely to be pulled down by
low extremes.
Histograms are best used to - Answers - Assess the shape of the distribution.
Chebyshev's Theorem says that at least 95 percent of the data lie within 2 standard
deviations of the mean. - Answers - False: At least 75 percent by Chebyshev.
So far this year, stock A has had a mean price of $6.58 per share with a standard
deviation of $1.88, while stock B has had a mean price of $10.57 per share with a
standard deviation of $3.02. Which stock is more volatile? - Answers - They are the
same: They are the same: CVA = 100(1.88/6.58) = 28.57%. CVB = 100(3.02/10.57) =
28.57%.
Which probability model is most appropriate to describe the waiting time (working days)
until an office photocopier breaks down (i.e., requires unscheduled maintenance)? -
Answers - Exponential: Poisson breakdowns suggest exponential waiting time.
If GMAT scores for applicants at Oxnard Graduate School of Business are N(500, 50),
then the top 5 percent of the applicants would have a score of at least (choose the
nearest integer) - Answers - 582: The top 5 percent would require z = 1.645, so x = 500
+ 1.645(50) = 582.25.
As n increases, the standard error decreases. - Answers - True: The standard error is
the standard deviation divided by the square root of the sample size.
A higher confidence level leads to a narrower confidence interval, ceteris paribus. -
Answers - False: Higher confidence requires more uncertainty (a wider interval). For
example, z0.025 = 1.960 (for 95 percent confidence) gives a wider interval than z0.05 =
In a bimodal histogram, the two highest bars will have the same height. - Answers -
False: Not necessarily, though they might be the same.
A frequency distribution is a tabulation of n data values into classes called bins. -
Answers - True: This is the definition of a frequency distribution.
The coefficient of variation is - Answers - A unit-free statistic.
Outliers are data values that fall beyond ±2 standard deviations from the mean. -
Answers - False: Outliers are 3 standard deviations from the mean
In a left-skewed distribution, we expect that the median will be greater than the mean. -
Answers - True: When there is left skewness, the mean is likely to be pulled down by
low extremes.
Histograms are best used to - Answers - Assess the shape of the distribution.
Chebyshev's Theorem says that at least 95 percent of the data lie within 2 standard
deviations of the mean. - Answers - False: At least 75 percent by Chebyshev.
So far this year, stock A has had a mean price of $6.58 per share with a standard
deviation of $1.88, while stock B has had a mean price of $10.57 per share with a
standard deviation of $3.02. Which stock is more volatile? - Answers - They are the
same: They are the same: CVA = 100(1.88/6.58) = 28.57%. CVB = 100(3.02/10.57) =
28.57%.
Which probability model is most appropriate to describe the waiting time (working days)
until an office photocopier breaks down (i.e., requires unscheduled maintenance)? -
Answers - Exponential: Poisson breakdowns suggest exponential waiting time.
If GMAT scores for applicants at Oxnard Graduate School of Business are N(500, 50),
then the top 5 percent of the applicants would have a score of at least (choose the
nearest integer) - Answers - 582: The top 5 percent would require z = 1.645, so x = 500
+ 1.645(50) = 582.25.
As n increases, the standard error decreases. - Answers - True: The standard error is
the standard deviation divided by the square root of the sample size.
A higher confidence level leads to a narrower confidence interval, ceteris paribus. -
Answers - False: Higher confidence requires more uncertainty (a wider interval). For
example, z0.025 = 1.960 (for 95 percent confidence) gives a wider interval than z0.05 =
